Primarily Studies On Phylogeography Of Chimonanthus Nitens Oliv.Complex (Calycanthaceae)

The genus Chimonanthus (Calycanthaceae) which is endemic species in Chinaoriginate from the Tertiary period. It cantain6species: Ch. praecox, Ch.campanulatus, Ch. salicifolius, Ch. nitens, Ch. zhejiangensis, Ch. grammatus.Chimonanthus have a long cultural history and important status in the landscape. Italso can be used as traditional Chinese medicine and health care products. In ourstudy, we research1) interspecific relationships by populations based on chloroplastDNA and ITS sequence (15populations,one population in Calycanthus chinensisused as outgroup);2) genetic diversity and population structure based onmicrosatellite in Chimonanthus.There are main results of our study:1Phylogeographic study based on sequence analysisThrough filter, two cpDNA intergenic spacer (trnS-trnG and rps16-trnK) andnuclear sequence ITS are used for our study. It’s19variable sites and10haplotypesin trnS-trnG (Haplotypes diversity=0.654, nucleotide diversity=0.00478).31variablesites and14haplotypes are detected in rps16-trnK (Haplotypes diversity=1.000,nucleotide diversity=0.00748). Higher variations are found in ITS (61variable sites,14halotypes, Haplotypes diversity=1.000, nucleotide diversity=0.02222). A total of27haplotypes are detected in combine data. The genetic relationship is far betweenCh. nitens complex and others showed in phylogenetic trees and TCS network. Therelationship in complex is hard to distinguish because of the radiation distribution inTCS network. The genntic differentiation coefficient (Gst) is0.96335and gene flow(Nm) is0.01in Chimonanthus. Analysis of AMOVA demonstrate that high geneticdifferentiation are detected among species. There are positive correlation betweengenetic distance and geographical distance. In Ch. nitens complex, Gstis0.89354andNmis0.03, and the higher genetic differentiation are detected among populations.It’s two branch in Chimonanthus. One cluster include Ch. praecox and Ch.campanulatus. Another is Ch. nitens complex which made up by the other4species.They come from the recent common ancestor. From TCS, we speculated that the origin of complex species should be in the wuyi mountain area. But the specificlocation needs to comfirmed by more populations.2Genetic diversity and population structure study based on SSRThey are15pair primers are designed for analysis genetic structure inChimonanthus (SSR68and SSR112are not suited to Ch. praecox). All primers don’texist linkage disequilibrium. The13pairs primers suited for Chimonanthus are usedfor13populations (269individuals) and219alleles are detected. The averageexpected heterozygosity is0.688and The average observed heterozygosity is0.742.The average PIC is0.650. Ch. praecox and Ch. campanulatus have special clusteringstatus and special gene pool showed in PCoA, Structrue and UPGMA. In Ch. nitenscomplex, Ch. salicifolius and Ch. nitens have closer species relationship because ofsame gene pool. Ch. grammatus have special gene pool and closer with Ch.salicifolius and Ch. nitens than Ch. zhejiangensis. Population YS in Ch. nitens ismore similar with Ch. zhejiangensis. So we guess Ch. zhejiangensis and Ch. nitensare the same species. The main variation in Chimonanthus existed in population. Itdoes not deviate HW balance signally. Heterozygote excess are detected in everypopulation which is caused by the founder effect because of no battleneckphenomenon. It’s positive correlation between genetic distance and geographicaldistance.